Electroless plating is carried out in a single steel tank so that necessary cleaning is apt to delay or interrupt production. The longer a tank is used, the more difficult it is to clean. Prior art tanks are made of lined steel or stainless steel and thus are too heavy to be easily moved, and the evacuating pipes and pump are usually built into the tank, reducing operative volume and rendering operation and cleaning more difficult.
The object of this invention is to provide an electroless plating structure obviating these drawbacks.